Longer lasting batteries

Fuel cells and radioactive isotopes could prolong power to mobile and micro devices

By
Charles Bermant & Ursula Seymour
| 06 Nov 2002

New ways to power devices are very much at the forefront of technology. As mobile computing becomes more prevalent and offers higher performance, coming up with a portable, long-lasting means to power it is the question that is taxing developers.

One method that might offer a solution is fuel cell technology which provides a means to increase battery power tenfold.

US company Neah Power Systems is one of those setting the stage for what it considers the next way to power electronic devices. A fuel cell is a device that converts hydrogen and oxygen into electricity and heat. It resembles a perpetually recharging battery, and would actually slide into a standard-size battery to recharge it. Because the rechargeable element is a small cartridge, users could ditch their extra battery units and AC adapters and carry cartridges instead.

Neah Power's technology uses methanol which has several advantages as a fuel according to director of product marketing, Gregg Makuch. It's powerful, inexpensive and environmentally friendly.

It's not clear yet how such fuel cells will be used in notebooks or other portable electronic devices, but the technology is drawing interest because of its longevity. The cells could either lengthen the time a digital device can run, or run more powerful devices than batteries can now support say Neah Power executives.

"Today's notebook PC manufacturers are leaving out a lot of functions due to power restrictions," says Makuch. "Faster processors, read/write DVD drives and other components are driving a need for more power, and Wi-Fi technology is driving people toward a 'power persistent' computer that you can take anywhere and stays on all the time".

But the first fuel cell-driven PCs are at least three years from market, the Neah Power executives expect.

Another future technology, designed to power much smaller devices like remote sensors or medical implants, involves harnessing the power of radioactive isotopes and using this to fuel tiny batteries inside such nanomachines, according to its developers at Cornell University.

Cornell professor Amit Lal has created a battery that measure just 1mm but can run for decades, reports the EE Times. The battery translates the stored energy from the isotope directly into the motion of a microscopic cantilever, enabling it to move components directly or to generate electricity for circuitry.

In theory the power from radioactive isotopes could last up to 100 years, but Lal says that they will only operate properly for around 50 years. Some isotopes also carry the benefit of being impervious to environmental conditions, such as temperature, which can affect the lifetime of normal batteries.